RoHS and PCB Manufacturing
Cause common six PCB substances are restricted by RoHS, the removal of lead has presented the greatest challenge for PCB manufacturers. Let’s discuss the reason in this article.
Board Finish-- Most bare circuit boards are now finished with a lead-free coating. There are a ton of varieties to choose from, including ENIG, immersion metal, and lead-free HASL.
Component Assembly-- Lead-free solder requires a higher temperature to bake components onto bare boards, which can have a huge effect on which parts you choose at design time.
Higher Melting Temperature-- Lead-free solder requires a higher melting temperature at 441°F, compared with a traditional tin/lead solder which melts at 356°F. Components also need to be able to withstand this higher temperature which can completely change how they’re designed and manufactured.
Mixed Process-- Since lead and lead-free boards require completely different temperatures, this also requires separate manufacturing processes. Two different production lines have to use, one is for leaded and another is for non-leaded electronics. However, this directly means the manufacturing cost will be increase a lot.
PCB Component Supplier-- Removing lead means you need to purchase PCB components from new qualified suppliers. It is not as easy as you have thought.
Shelf Life-- Boards manufactured with lead-free solder and finishes typically have a shorter lifespan due to higher moisture sensitivity. This can be a strong consideration for applications that need to last years or decades in the field in extreme conditions.